Microstrip patch antenna (“patch antenna”) is widely used in wireless communication systems due to, for example, its low cost, high reliability, and compact size. Harmonic distortions produced by radio frequency (RF) devices in communication systems coupled to the patch antenna, including power amplifiers, may radiate through the antenna, causing degradation in the performance of the wireless communication system.
In current communication systems, to suppress the harmonic radiation, frequency filtering circuit, such as the band pass filter, may be incorporated into the system. In addition to increasing the size and cost of the communication system, the filter circuit are a source of insertion loss.
Several other approaches include using harmonic radiation suppressed antenna. It has been reported that photonic bandgap and defected ground structure suppressed harmonic frequencies, as well as usage of shorting pins and slots, may be used to shift the harmonic frequencies toward higher frequency than a fundamental frequency and removing the harmonic distortions at the higher frequency. However, these techniques have drawbacks including deformation of radiation pattern at the fundamental frequency and reduced antenna gain.
Therefore, what are needed are devices, systems and methods that overcome challenges in the present art, some of which are described above.